Control Board Holder Structure to Prevent Warping in Rotating Machines

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Solution Overview

Problem

Conventional rotating electrical machines face challenges in suppressing warping and distortion of control boards due to external loads during assembly, particularly when using heat dissipating materials, as existing configurations fail to stabilize the board's alignment with heat sinks.

Innovation Solution

A rotating electrical machine design featuring a control board with a power circuit portion covered by a heat dissipating material, a holder with protrusions that overlap the power circuit, and a support member to stabilize the holder, which includes protrusions to prevent warping and distortion by enhancing adhesion without bending the board.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a protrusion and heat dissipating material are formed on the same surface to enhance adhesion, then adhesion between control board and heat dissipating material is improved, but warping and distortion of the control board worsen due to bending to the opposite side of the protrusion during assembly

Engineering Contradiction:

Improveadhesion between control board and heat dissipating materialVSAvoidwarping and distortion of control board

Core Design Contradiction:

StrengthVSShape

Solution Approach 1:

The holder is divided into multiple protrusions (first, second, and third protrusions) with different functions: first protrusions for positioning, second protrusions for preventing warping by contacting the back surface, and third protrusions for enhancing adhesion. This segmentation allows each protrusion type to address specific issues without causing the harmful effects of the unified design.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The holder acts as an intermediary component between the control board and the heat dissipating material. It provides a stable supporting structure that distributes loads and prevents direct contact between the heat dissipating material and the control board back surface, thereby preventing warping while maintaining adhesion.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Strength

If external load is applied to the heat dissipating material to enhance adhesion, then adhesion is improved, but warping and distortion of the control board worsen

Engineering Contradiction:

ImproveadhesionVSAvoidstability of control board alignment

Core Design Contradiction:

StrengthVSStability of the object's composition

Solution Approach 1:

Different regions of the holder provide different functions: first protrusions provide localized positioning at specific points, second protrusions provide distributed support across the back surface to prevent warping, and third protrusions provide localized adhesion enhancement. This local differentiation allows the system to achieve both strong adhesion and stable alignment.

Inventive Principle:

Principle #3Local quality

3Shape

If a protrusion of truncated cone shape is formed in the heat sink with a corresponding hole in the control board to reduce warping, then warping is reduced, but stable suppression of warping and distortion is difficult due to variations in shape of the protrusion and hole

Engineering Contradiction:

Improvewarping reductionVSAvoidalignment stability between protrusion and hole

Core Design Contradiction:

ShapeVSManufacturing precision

Solution Approach 1:

The positioning function is separated from the warping prevention function. First protrusions with positioning grooves provide precise alignment, while second protrusions provide warping prevention. This segmentation ensures that alignment stability is not compromised by the variations in protrusion and hole shapes.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The mechanical interference fit of the truncated cone protrusion and hole is replaced by a positioning groove system. The positioning grooves engage with the first protrusions to provide stable alignment, eliminating the sensitivity to shape variations inherent in the truncated cone design.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The design effectively suppresses warping and distortion of the control board, ensuring stable heat dissipation and preventing voltage drops, short circuits, and solder damage, thereby improving the reliability and heat dissipation performance of the machine.

Implementation Method 1

a heat dissipating material 35 covering the power circuit portion S2. Heat generated by the power circuit portion S2 is dissipated to the heat sink 50 through the heat dissipating material 35

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

heat sink 50 connected to the control board 4

Methodology Applied

Scientific EffectConvection: Convection

Implementation Method 3

heat sink 50 connected to the control board 4

Methodology Applied

Scientific EffectThermal radiation: Thermal Radiation

Data Source

PatentUS12451770B2Rotating electrical machine

Publication Date: 2025.10.21 MITSUBISHI ELECTRIC CORP

AI summary

A rotating electrical machine includes a control board that has a control circuit portion on a main first surface, a power circuit portion, and a heat dissipating portion that covers the power circuit portion, a holder that opposes a second main surface of the control board which is an opposing surface to the first main surface, and a support member that supports the holder, wherein the holder includes a plurality of protrusions that project towards the second main surface, and at least a portion of the plurality of protrusions are disposed so as to overlap with the power circuit portion in a plan view.